for computer-computer conversations i use skype. just need headphones/microphone and you can talk. free!
but to talk to landline in europe i use inphonex. it works with the internet and telephone line thou you do not have to have your computer on to use a phone. you can have either pre-paid credit or a calling plan. i think it costs around 25 bucks a month and you have unlimited calls to usa and canada plus a number in the usa, so your family can call you paying local rates.
for a long term this is the best solution, i think.
you'd have to buy and install the box but then you can use it anytime and take it with you wherever you may move.
VoIP Service Providers, free Internet Telephony unlimited VoIP Phone Calls
that's their website.
welcome to DR.